Description
Given an integer x, return true if x is a palindrome, and false otherwise.
Example 1:
Input: x = 121 Output: true Explanation: 121 reads as 121 from left to right and from right to left.
Example 2:
Input: x = -121 Output: false Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.
Example 3:
Input: x = 10 Output: false Explanation: Reads 01 from right to left. Therefore it is not a palindrome.
Constraints:
-231 <= x <= 231 - 1
Follow up: Could you solve it without converting the integer to a string?
Solution
Python3
class Solution:
def isPalindrome(self, x: int) -> bool:
x = str(x)
i, j = 0, len(x)-1
while i < j and x[i] == x[j]:
i += 1
j -= 1
return i >= j